Tunable lasers, which are lasers that may be tuned to emit light at various wavelengths, are widely used in optical communications. It is desirable for tunable lasers to be able to emit light across the full C band, which refers to the spectrum between about 1,528 nanometers (nm) and about 1,565 nm. Different approaches are used to achieve full C-band tunability. One approach is a monolithically-integrated laser, which comprises both a gain medium and a cavity formed on an indium phosphide (InP) substrate. Another approach is an external cavity laser, which comprises a cavity constructed of bulk optics, a collimator lens, a liquid crystal or microelectromechanical systems (MEMS) tunable mirrors, and other components. It is also desirable to achieve full C-band tunability with accuracy and power conservation.